Professor, informally eften kent as full professor, is the heichest academic rank at varsities an ither post-seicontar eddication an resairch institutions in maist kintras. Leeterally, professor derives frae Laitin as a "person wha professes" bein usually an expert in airts or sciences, a teacher o the heichest rank.[1] In some kintras, the wird professor is an aa uised in teetles o lawer ranks such as associate professor an assistant professor.